Today in history: April 1

April Fools' Day, celebrated today with joking relationships and practical jokes. It may have grown out of the medieval Feast of Fools, which was held on January 1.

2001: The midair collision of a U.S. spy plane and a Chinese fighter jet that was tailing it over the South China Sea resulted in the death of the Chinese pilot and the landing of the damaged American plane on Hainan Island, where its crew was detained for 11 days.

1999: Created this day in 1999 by carving a vast region from Canada's Northwest Territories, the Canadian territory of Nunavut stretches across much of the Canadian Arctic and encompasses the traditional lands of the Inuit.

1984: American entertainer Marvin Gaye was shot and killed by his father in Los Angeles.

1982: The United States transfers control of the Panama Canal Zone to Panama.

1970: The U.S. Army charges Captain Ernest Medina for his role in the My Lai massacre.

1968: The U.S. Army launches Operation Pegasus, the reopening of a land route to the besieged Khe Sanh Marine base.

1954: The United States Air Force Academy was created by an act of Congress and was later built in Colorado Springs, Colorado.

1951: United Nations forces again move northward across the 38th Parallel in Korea.

1948: The Berlin Airlift begins, relieving the surrounded city from the Soviet siege.

1945: U.S. troops landed on the Japanese island of Okinawa during World War II.

1942: The U.S. Navy begins a partial convoy system in the Atlantic.

1939: The Spanish Civil War effectively ends with the official recognition of Franco's government.

1929: The yo-yo is introduced in the United States by Louie Marx.

1928: China's Chiang Kai-shek begins attacks on communists.

1924: Adolf Hitler sentenced to five years in prison for the "Beer Hall Putsch."

1920: Germany's Workers Party changes its name to the Nationalist Socialist German Worker's Party (Nazis).

1918: The United Kingdom's Royal Air Force was formed.

1917: American composer and pianist Scott Joplin died in a mental institution in New York City.

1905: Berlin and Paris are linked by telephone.

1868: The Hampton Institute is founded in Hampton, Va.

1865: At the Battle of Five Forks, Gen. Robert E. Lee begins his final offensive.

1863: The first wartime conscription law goes into effect in the United States.

1778: Oliver Pollock, creates the dollar sign.

1578: English physician William Harvey, who discovered the true nature of the circulation of the blood, was born in Folkestone, Kent.

1572: The Sea Beggars under Guillaume de la Marck land in Holland and capture the small town of Briel.